Method for assembling a multi-piece apparatus

ABSTRACT

An improved fluid level verification apparatus for use on liquid filled containers and configured to reduce inherent mechanical stresses on the inspection tube and resist leakage due to environmental, chemical, thermal or mechanical expansion cycles by using a protective shield member to encase the inspection sight member, and, also, a method for permanently sealing the fluid level detection apparatus.

RELATED APPLICATION

This is a divisional patent application of patent application Ser. No.10/065,560, filed 30 Oct. 2002 now U.S. Pat. No. 6,756,092.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a fluid level verificationapparatus which is operable to measure the amount of fluid present in afluid container, such as a tank, machine, or other article ofmanufacture, and more specifically, to an apparatus which may bemanufactured or otherwise fabricated as a kit for use on particularmachines or in manufacturing processes; and which minimizes the numberof components required; and further to a fluid level verificationapparatus which reduces mechanical, thermal and chemical stresses on theapparatus.

2. Description of the Prior Art

The prior art is sated with examples of fluid level verificationapparatuses which provide a means for visually verifying or otherwisediscovering the fluid levels in an object of interest, such asmanufacturing machinery, fluid holding tanks, or other similarassemblies. For example, in certain industrial processes or in certainmachines or other articles of manufacture, it is important thatparticular fluids, such as lubricants, coolants, hydraulic fluids, orother fluid components, be stored in tanks and periodically dispensedfrom such tanks. Prior art fluid verification devices have typicallyincluded a transparent tube or inspection window, which is connected inparticular relation to the holding tank, and which provides a quick andconvenient means by which an observer may visually verify the level ofthe fluid present.

While the prior art devices have operated with success, they have beenunsatisfactory in several respects.

Gruett, U.S. Pat. No. 5,323,653, assigned to the same assignee as thepresent application, provides a detailed background of the prior art anddescribes a fluid level verification apparatus that can be fabricated asa kit and assembled at a remote location. Gruett contemplates aninspection tube having an interior conduit dimensioned to create aninterference fit with an o-ring used to hermetically seal the inspectiontube to an end member. The Gruett apparatus requires a separate seal onthe outer diameter of its glass inspection tube to complete a hermeticseal.

Jackson, U.S. Pat. No. 4,345,468, describes a double tube liquid sightmonitor, which incorporates grooving and o-rings to isolate theinspection tube from the environment. However, the Jackson invention isrelatively complex and cumbersome, as it requires numerous parts toprotect the inspection tube from the stresses caused by the environment.Moreover, the sealing function of the grooves are limited to the insertends thus requiring the o-rings to rest against the internal andexternal surfaces of inspection tubes that have no such grooves and theproblem of mechanical stress induced by the assembly of the inspectiontubes to mating components is not contemplated.

Evans, U.S. Pat. No. 4,050,305, describes an external shield bracket fora fluid flowmeter. The fluid of interest flows through a precision glasstube. An operator is protected from accidental explosion of theinspection tube due to fluid pressure by a protective transparent covermounted on a U-shaped channel bracket. The Evans invention uses manyparts, but fails to protect the inspection tube from the environment.Furthermore, this transparent cover and mounting bracket do not form ahermetic closure for the inspection tube contained therein.

Gruett, U.S. Pat. No. 3,886,796, also assigned to the same assignee asthe present application, describes a liquid level gauge with a rigidtransparent plastic inspection tube with o-rings seated in grooveslocated in the end members. The Gruett invention was designed forassembly without the need of o-ring grooves on the exterior or interiorportions of the inspection tube. The ends of the inspection tube arerestricted and nested in the end members.

Lyden, U.S. Pat. No. 3,540,276, describes a fluid level gauge. The Lydeninvention uses an o-ring seal nested in an end member, communicatingwith the adjacent end of a sight tube. Fluid leaks are minimized byplacing the glass sight tube in compression with the o-ring seal nestedin the respective end member. The glass sight tube is required becausethe Lyden invention requires compressive force on the tube. Thus, thedesign creates inherent mechanical stress, and without utilizing theglass sight tube, adapts poorly to thermal, environmental and chemicalexpansion cycles and therefore is susceptible to leakage.

Lukas, U.S. Pat. No. 3,455,163, describes a liquid level gauge where theapparatus is backwardly attached to the liquid tank. The Lukas inventionallows for the inspection sight member to be fittingly secured withinthe support body by means of plugs placed at the ends of the inspectionsight member. However, the use of plugs to secure the inspection sightmember within the apparatus causes compressive stress on the inspectionsight member. Furthermore, the Lukas invention is not easily attached orremoved from a liquid tank.

One advantage of most prior art fluid level detection apparatuses is theease of replacing the inspection sight member without having to replacethe rest of the apparatus. However, the trend in recent years is thatusers of the apparatus are replacing the entire apparatus, even if onlythe inspection sight member needs to be replaced. Many of the prior artdevices are cumbersome and otherwise complex in their overall design,thereby increasing the cost to manufacture, decreasing the reliabilityand making them difficult to maintain. Further, the prior art is repletewith designs that inadequately address the often conflictingrequirements of resisting fluid leaks and protecting the inspection tubefrom mechanical, environmental, thermal and chemical stresses.Therefore, a need exits for a fluid level verification apparatus that issimple to manufacture yet durable and reliable in use.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide animproved fluid level verification apparatus.

Another object of the present invention is to provide a fluid levelverification apparatus which can be fabricated and remain assembledthrough subsequent handling, transport, and shipping operations.

Specifically, it is an object of the present invention to provide afluid level verification apparatus that requires no reassembly beforeuse for a wide range of devices and other objects of interest.

Yet another object of the present invention is to protect thetransparent inspection tube from mechanical stress during manufacture,transport, handling, shipping, assembly, and use for a wide range ofdevices and other objects of interest.

Another further object of the present invention is to provide a means toreduce or minimize stress on the apparatus, whether such stress is dueto thermal, mechanical, environmental or chemical agents acting upon theapparatus.

Still another object of the present invention is to provide a means toreduce or minimize leaking of the fluid flowing through the apparatus.

Still another further object of the present invention is to provideadded support to the inspection sight member without adding unnecessarystress to the inspection sight member.

Another further object of the present invention is to reduce or minimizestress to the sight member caused by interconnectivity of the endmembers, sight member, and the shield member of the apparatus.

Still another object of the present invention is to reduce or minimizeleaking of the fluid flowing through the apparatus, and doing so with aminimum amount of stress resulting on the sight member.

Still another object of the present invention is to reduce the number ofcomponents required for the resulting assembly thereby decreasingmanufacturing costs.

Another further object of the present invention is to provide a methodfor permanently connecting the end blocks of the apparatus to the shieldmember of the apparatus without adding stress to the inspection sightmember.

Still another object of the present invention is to provide an apparatusthat may contain a thermometer for measuring the temperature of thefluid flowing through the apparatus' conduit.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of the present invention, as it would appearin the environment;

FIG. 2 is an exploded isometric view of the cooperating components ofthe present invention;

FIG. 3 is a detailed isometric view of an end member used in the presentinvention;

FIG. 4 is an isometric fragmentary view detailing the end of the sighttube shield member used in the present invention;

FIG. 5 is an exploded isometric fragmentary view of the end memberillustrating its relationship with the shield member;

FIG. 6 is an isometric fragmentary view of the means used in securingthe end members to the shield member;

FIG. 7 a is a fragmentary elevated view of an alternative means used insecuring the end members to the shield member;

FIG. 7 b is a fragmentary elevated view of the second step for thealternative means of FIG. 7 a to connect the end members to the shieldmember;

FIG. 8 is a longitudinal sectional fragmentary view of the presentinvention taken along lines 8—8 of FIG. 1, and showing in detail, an endmember secured to the shield member.

FIG. 9 a is a front elevated view of another embodiment of thisinvention in which the sight member is arranged to receive a thermometerseated within the hollow bore of the sight tube.

FIG. 9 b is a side longitudinal sectional view of the thermometeradaptation of this invention taken along line 9 b—9 b of FIG. 9 a.

FIG. 10 a is a longitudinal sectional fragmentary view of an alternateembodiment of the present invention similar to the view of FIG. 8, andshowing in detail, an end member prior to being permanently secured tothe shield member.

FIG. 10 b is a longitudinal sectional fragmentary view of an alternateembodiment of the present invention similar to the view of FIG. 8, andshowing in detail, an end member secured to the shield member.

DETAILED DESCRIPTION

Although the disclosure hereof is detailed and exact to enable thoseskilled in the art to practice the invention, the physical embodimentsherein disclosed merely exemplify the invention that may be embodied inother specific structures. While the preferred embodiment has beendescribed, the details may be changed without departing from theinvention, which is defined by the claims. Like parts, described herein,are designated by like reference numbers.

Referring to FIG. 1, there is illustrated an embodiment of an improvedfluid level verification apparatus utilizing a transparent tubularinspection sight member 10. The sight member 10 is encased and supportedby a shield member 12, said shield member 12 having a first end 14 and asecond end 16. Also depicted is a pair of substantially identical endmembers, or supporting blocks 18. Each block 18 has six sides and amounting bolt 20. One of the blocks 18 is permanently secured to theshield member 12 at the first end 14, and the other block 18 ispermanently secured to the second end 16. The means to permanentlysecure the end blocks 18 to the shield member 12 can be seen by notingthe indentations 22 at each end of the shield member 12, which willlater be described.

Referring next to FIGS. 2, 3, and 5, each end block 18 has an inwardlyfacing nipple 24 with an outwardly extending nipple extension 26 at theextremity of the nipple 24. The nipple extension 26 preferably has asmaller circumference than the nipple surface 28. The nipples 24 taperoutwardly from the respective nipple bases 30 at the faces 18 f of endblocks 18 to the respective nipple surfaces 28.

With particular reference to FIG. 2, the inspection sight member 10,with its respective ends 32 and 34, is placed inside of the shieldmember 12. The ends 32 and 34 are in contact with resilient o-ring endseals 36. Each end seal 36, in turn, is fittingly placed around arespective nipple extension 26 and sealingly engages the respective endsof the sight member 10 to minimize fluid leakage.

Referring to FIGS. 1 and 2, the sight member 10 is protected from theenvironment by the shield member 12. Ends 14 and 16 of the shield member12 extend longitudinally beyond ends 32 and 34 of the sight member.Opening 35 in the shield member 12 allows sight member 10 to be visiblewhile still being protected by shield member 12.

Again, with particular reference to FIG. 2, the shield member 12 has abore 71 longitudinally centered throughout the shield member 12. Thediameter of the bore 71 is slightly larger than the diameter of thesight tube member 10. The sight tube member 10 is telescopingly placedinside shield member 12.

Still with particular reference to FIGS. 2 and 9 b, the respectivemounting bolts 20 comprise a head 38, a hollow shank 40 (see FIG. 9 b),an external thread 42 and a cylindrical bore 44 with an inner diameter46. Interposed on the shank 40 at a right angle is an intersecting crosshole 48. The shank 40 terminates in a bolt head 38. The bolt head 38 hasa bolt face 50 and an underside 52. The underside 52 of the bolt face 50has an annular groove 54 (see FIG. 9 b) arranged to receive aconventional o-ring 56. The diameter of each of the re-entrant bores 58(see FIG. 9 b) of the respective blocks 18 is larger than the innerunthreaded portion 43 of the bolts 20 to provide sufficient spacing forfree flow of fluid through the hollow bore 44 of the bolt 20, the boltholes 48, the aperture 62 of the nipple 24 and the conduit 64 of thesight tube 10. The respective sides of the end blocks 18 have an annulargroove 65 to receive a resilient o-ring 67 (see FIG. 9 b).

With further reference to FIGS. 2 and 9 b, the sight member 10 isconnected in fluid flowing relation to an object of interest, such as atank (not shown). So connected, the compression exerted on therespective bolts 20 compresses the sealing gasket. 56 (see FIG. 9 b)against the face 18 b of the block 18, thus facilitating a hermeticclosure. Similarly, the seal 67 resting on the bolt 20 at the junctionof the thread 42 and the shank 40, is compressed at the annular groove65 creating a hermetic closure of the seal 67, the annular groove 65 andthe bore 58 of the block 18. Seal 67 also seals against the tank surface(not shown) to prevent leakage around the thread 42 when the fluid levelverification apparatus is mounted to the tank.

Fluid dispensed from and returning to the object of interest, such as atank (not shown but including an entrance threaded opening matching thethreads 42 of the bolts 20), flows through the bolt 20 by means of there-entrant bore 44, and the block 18 by means of the bore 58 in theblock 18, and cooperating with the cross hole 48. Fluid enters theaperture 62 of the nipple 24, and fills the conduit 64 of the inspectionsight tube member 10 to the liquid level of the tank supporting thesight member 10.

Referring specifically to FIG. 3, each block 18, preferably includes aplurality of faces, 18 a, 18 b, 18 c, 18 d, 18 e, and 18 f. Acylindrical nipple extension 26 of said nipple 24 protrudes at agenerally perpendicular offset from the face 18 f of the respective endblocks 18. The nipple 24 has an aperture 62, which extends through thenipple 24 and the nipple extension 26 to intersect a bore 58 of theblock 18, and is oriented generally parallel with the axis of the nipple24.

Still referring particularly to FIG. 3, the nipple 24 is of apredetermined nipple height 66. The nipple 24 has a nipple base 30. Thecircumference of the nipple 24 tapers outward from the nipple base 30 tothe nipple surface 28, with a minimum circumference at the nipple base30, to a maximum circumference at the nipple surface 28. Thecircumference of the nipple extension 26 is smaller than that of thenipple base 30 or the nipple surface 28. The aperture 62 concentricallyruns through the nipple 24 and the nipple extension 26, allowing for afree flow of fluid in communication with the bore 58 of the end block18.

With particular reference to FIG. 4, a fragmented view of the sight tube10 and the shield member 12 is shown in connection with the shieldmember end 14. On the inside of the shield member 12 at said end 14 areconcentric grooves 68 and 70. Concentric groove 68 has a slightly largerdiameter than the inner diameter of the bore 71 running through theshield member 12. The larger diameter of groove 68 results in a thinnersection of the shield member 12 at that point, thereby easing theeventual indentation 22 (see FIG. 8) of the shield member end 14, andwill hereinafter be described.

In FIG. 5, the end block 18 is shown enroute to placement inside theshield member 12. Nipple 24 has a diameter 72 essentially the same asthe diameter of the bore 71 at the end 14 of the shield member 12, withjust enough difference to allow the nipple 24 to fittingly slide throughthe shield member bore 71. Face 18 f of the end block 18 will abut thetop face 74 of the shield member 12. The nipple extension 26 will nestleinto the inner diameter of end seal 36. The end seal 36 (not shown inFIG. 5) is seated between the sight tube 10 and the nipple 24. The faces18 f and 74 meet in such a way that the nipple height 66 longitudinallyextends into the tube shield bore 71 so that the end of the nippleextension 26 may be at the same latitude as that of the end 32 of thesight tube 10. However, it should be noted that the diameter of nippleextension 26 is small enough not to interfere with the inner diameter ofsight member 10.

Referring particularly to FIGS. 6 and 8, a means for permanentlysecuring the block end 18 to the end 14 of the shield member 12 isshown. Conventional tool steel punches 76 are used to indent or stakeopposing sides 12 a and 12 b of the shield member 12. The punches 76will preferably come in at the latitude where groove 68 (see FIG. 8) islocated on the shield member 12. The punches 76 form the indentations 22in each of the respective sides 12 a and 12 b of the shield member 12,which cause detents 80 at the approximate latitude said groove 68 islocated (see FIG. 8). It is within the purview of the present inventionto incorporate one, two, three or more punches 76 simultaneously or atvarious intervals during the staking operation.

FIG. 7 a shows means for an alternative method of permanently connectingthe end block 18 to the shield member 12. The block end 18 and theshield member 12 are placed squarely together so that the side 12 b isflush against a flat surface 78. The punch 76 forms the indentation 22on the side 12 a of the shield member 12 which is opposed to the side 12b touching the flat surface 78. The indention 22 is at the latitude inthe shield member 12 where said groove 68 is located, forming the detent80 at the approximate latitude said groove 68 is located (see FIG. 8).

FIG. 7 b shows the means for continuing the process in FIG. 7 a. The endblock 18 and the shield member 12 are rotated 180 degrees. Side 12 a isnow flush against the flat surface 78. The punch 76 comes in contactwith side 12 b to form an indention 22 at the latitude in the shieldmember 12 where groove 68 is located, forming the detent 80 at theapproximate latitude said groove 68 is located (see FIG. 8).

FIG. 8 shows a fragmentary cross-sectional view of the fluid leveldetection apparatus 9 after the end block 18 and the shield member 12have been connected and secured. The cross-sectional view of theapparatus shows the sight tube member 10 fittingly connected with theend seal, or o-ring 36. The end seal 36 is shown seated between thesight tube member 10 and surrounding the nipple extension 26. Anunblocked passageway is shown between the hollow bore 58 of the endblock 18, the cross hole 48 of the bolt shank 40, the aperture 62through the center of the nipple 24, and the conduit 64 passing throughthe sight member 10. The indention 22 forms a detent 80 at theconcentric groove 68, which securely engages the nipple 24 to hold theend block 18 in place.

Next, with particular attention to the views of FIGS. 9 a and 9 b, itwill be observed that the verification apparatus of this invention mayalso be used in connection with thermometers or other devices requiringprotection from the elements. Again, like parts are indicated utilizinglike reference characters.

The hollow shield member 12 houses a protective tubular sight or sightmember 10. The bore or inner diameter 11 of the sight member 10, inturn, may house an elongated thermometer 13 held in place by means oflongitudinally spaced o-rings 15. The o-rings 15 are preferablyexpandable to hold the thermometer 13 in compression against the innerdiameter 11 of the tubular sight 10. The thermometer 13 may be of knownconstruction and comprise an elongated transparent tube housing a heatexpandable substance, such as dyed mineral spirits, mercury and/or otherequivalent materials 17. The tubular thermometer 13 is conventionallypositioned adjacent a backing temperature indicating plate 19, includingnumbered indicia arranged to indicate the temperature of fluid, such asheated water or oil, passing through the conduit 64 of the sight member10.

As will be noted from the views of FIGS. 9 a and 9 b, the variouscooperating components of the present apparatus embodiment act insimilar fashion as the components illustrated and described inconnection with the views of FIGS. 1-8, inclusive. The bolts 20 arearranged to be seated in the bores 58 of the respective end blocks 18,and respectively include re-entrant bores 44, which intersect aperture62 of the end blocks 18. The bolts 20 are appropriately sealed to theend block 18 by means of o-rings 56 seated there between.

An alternative construction of the seal between each site member 10,shield member 12 and end block 18 is shown in FIGS. 10 a and 10 b. Theconfiguration of the nipple 24 extending from side 18 f of end block 18has been replaced with an annular skirt 90 having a groove 92 formedtherein. The counter bore 71 formed in the shield member 12 has beenextended inwardly. In contrast to the above-described embodiment, theo-ring 36 is now placed around the smooth outer perimeter of site member10. When the outermost surface 94 of the annular skirt 90 of end block18 is placed into the counter bore 71 of the shield member 12, theo-ring 36 is slightly compressed forming a hermetic seal between thesite member 10, shield member 12 and end block 18. In contrast to theabove-described embodiment, this arrangement prevents the necessity ofputting the site member 10 under any axial compression.

It is also desirable to have a press fit between the counter bore 71 ofshield member 12 and annular skirt 90 of end block 18. The press fitaids during assembly in that it is not necessary to retain the shieldmember 12 and end block 18 under compression during the staking process.As shown in FIG. 10 b, once the site member 10, shield member 12 and endblock 18 are assembled, a greater variation is allowed for the exactlocation of the stake on each side of the shield member 12 withoutcompromising the critical seal.

The sight tube 10 may be manufactured from glass. However, varioussubstrates such as nylon, polycarbonate, or other synthetic materialsmay be used. While shown to be cylindrical in shape, it is conceivablethat other conduit cross-sectional configurations could be utilized.

The shield member 12 and the end blocks 18 may be manufactured fromaluminum, or other metals with similar malleable qualities of aluminum.

The above-described embodiments of this invention are merely descriptiveof its principles and are not to be limited. The scope of this inventioninstead shall be determined from the scope of the following claims,including their equivalents.

1. A method for assembling a multi-piece apparatus, said methodcomprising: providing a first member having an internal bore; providinga second member having an axially extending, circumferentially groovednipple portion arranged to be received within said internal bore of saidfirst member; inserting the nipple portion of said second member intosubstantial engagement with the bore of said first member; indenting aside wall surface proximal an end of the first member to deform andprovide at least one inwardly formed indent engageable with saidcircumferentially grooved portion of said second member.
 2. A method forconnecting an end member to a main member, the method comprising thesteps of: providing a main member having at least one opening; providingat least one end member having an outwardly tapered axially extendinggrooved nipple portion; placing said outwardly tapered axially extendingnipple portion of said at least one end member inside the at least oneopening formed in the main member; and indenting said main member toprovide an inwardly projecting detent engageable with the tapered grooveformed in the nipple portion, so as to clamp said main member onto thetapered groove of said end member.
 3. A method for assembling a fluidlevel verification apparatus for a fluid container, said methodcomprising: providing a shield member having an internal bore forencasing a sight member; providing a tubular sight member having athrough bore; providing an end member having a circumferentiallygrooved, axially extending, nipple portion; placing said tubular sightmember within the internal bore of said shield member; inserting theaxially extending nipple portion of said end member into substantialengagement with the respective end of the bore of said shield member andinto sealing engagement with the sight tube through bore; indenting afirst side of the shield member to deform and provide at least onedetent engageable with the circumferentially groove of said nippleportion.
 4. A method for connecting respective end members to a shieldmember having a through bore in a fluid level verification apparatushaving a tubular sight members, thereby sealing the end members to theshield member, the method comprising the steps of: providing oppositelydisposed end members each having an axially extending, circumferentiallygrooved, outwardly tapered nipple portion arranged to be received withinopposite ends of the through bore of said shield member; placingrespective outwardly tapered nipple portions of the respective endmembers inside openings formed in the shield member ends; abutting theoutwardly tapered nipple portions of each of said end members torespective sealing means which are positioned at opposite ends of thetubular sight member and the inwardly disposed ends of each of thenipple portions of the respective end members; and indenting said shieldmember at at least one of its proximal ends to deform and provide atleast one inwardly projecting detent engageable with thecircumferentially grooved, outwardly tapered axially extending nippleportion so as to clamp said respective end of the shield member to therespective end member.
 5. The method of claim 4, further including thestep of clamping each of the end members to each of the respectiveaxially extending, inwardly disposed nipple portions.